When talking about managing one's money, sales expert Grant Cardone likes to quote another well-known entrepreneur, Mark Cuban. “Diversification is for idiots.” 

But what does that mean? As Cardone puts it, you can never attain true financial wealth by diversifying your investments.

Yes, you need to depend on more than one flow of income, he says. But when you invest, make sure its in a controlled number of places that you have intimate knowledge of. 

"You want to find one or two spaces you completely understand, that can't be destroyed, and go all in," Cardone says. "That's how people get rich. People don't get rich by tip-toeing in with $100 investments all over the place."

For more investment tips, and to find out the one thing Cardone invests his money in, watch the video above.

Related: 8 Money Mistakes to Avoid on Your Way to Being Wealthy